Are you reading this page on a computer plugged into an electrical socket? If you are, that electricity is probably coming from burning coal or natural gas. Once upon a time, that would have been the end of the story. Today, electricity generation is buffeted by numerous factors: access to fossil fuels, peak oil, nuclear security and proliferation, pollution, and climate change. So depending on where you live, nuclear fission and high-pressure dammed-up water might be contributing to your local energy mix as well. Solar and wind power still play a comparatively small role, but because they’re basically inexhaustible and release no carbon pollution, intensive research is aiming to harvest them more efficiently and inexpensively. An even better long term solution might be to construct some mini-Suns right here on Earth—that’s effectively the goal of nuclear fusion research, though practical implementation is still a ways off.

Maybe you’re reading on a tablet with a rechargeable battery? Energy storage devices like batteries will be crucial to making solar and wind energy practical, since it isn’t always bright and windy. Splitting water to make hydrogen is another storage mechanism being studied. Biofuels, too, are essentially a means of bottling solar energy. We’ll keep you up to date on this ever-shifting landscape as scientists strive to create cleaner, more sustainable, and more affordable ways to keep the lights burning.